Reading CSV file in Go

Go now has a csv package for this. Its is encoding/csv. You can find the docs here: https://golang.org/pkg/encoding/csv/

There are a couple of good examples in the docs. Here is a helper method I created to read a csv file and returns its records.

package main

import (
    "encoding/csv"
    "fmt"
    "log"
    "os"
)

func readCsvFile(filePath string) [][]string {
    f, err := os.Open(filePath)
    if err != nil {
        log.Fatal("Unable to read input file " + filePath, err)
    }
    defer f.Close()

    csvReader := csv.NewReader(f)
    records, err := csvReader.ReadAll()
    if err != nil {
        log.Fatal("Unable to parse file as CSV for " + filePath, err)
    }

    return records
}

func main() {
    records := readCsvFile("../tasks.csv")
    fmt.Println(records)
}

Go is a very verbose language, however you could use something like this:

// predeclare err
func parseLocation(file string) (locations map[string]*Point, err error) {
    f, err := os.Open(file)
    if err != nil {
        return nil, err
    }
    defer f.Close() // this needs to be after the err check

    lines, err := csv.NewReader(f).ReadAll()
    if err != nil {
        return nil, err
    }

    //already defined in declaration, no need for :=
    locations = make(map[string]*Point, len(lines))
    var lat, lon float64 //predeclare lat, lon
    for _, line := range lines {
        // shorter, cleaner and since we already have lat and err declared, we can do this.
        if lat, err = strconv.ParseFloat(line[1], 64); err != nil {
            return nil, err
        }
        if lon, err = strconv.ParseFloat(line[2], 64); err != nil {
            return nil, err
        }
        locations[line[0]] = &Point{lat, lon}
    }
    return locations, nil
}

//edit

A more efficient and proper version was posted by @Dustin in the comments, I'm adding it here for completeness sake:

func parseLocation(file string) (map[string]*Point, error) {
    f, err := os.Open(file)
    if err != nil {
        return nil, err
    }
    defer f.Close()

    csvr := csv.NewReader(f)

    locations := map[string]*Point{}
    for {
        row, err := csvr.Read()
        if err != nil {
            if err == io.EOF {
                err = nil
            }
            return locations, err
        }

        p := &Point{}
        if p.lat, err = strconv.ParseFloat(row[1], 64); err != nil {
            return nil, err
        }
        if p.lon, err = strconv.ParseFloat(row[2], 64); err != nil {
            return nil, err
        }
        locations[row[0]] = p
    }
}

playground